Aproveitamento de resíduos agrícolas na composição de substratos para produção de mudas de cacaueiro (Theobroma cacao l.)

Abstract

The cultivation of cacao ( Theobroma cacao L.) has been expanding in the state of Amapá, requiring sustainable and economically viable strategies for producing high-quality seedlings. In this context, the use of agro-industrial residues, such as crushed açaí seeds, shows potential for the formulation of regional substrates. This study evaluated the growth of cacao seedlings produced in five substrate compositions containing crushed açaí seeds, terra preta, bovine manure, goat manure, and soil. The experiment was conducted in a completely randomized design (CRD), with five treatments and five replications, in a protected nursery at IFAP – Porto Grande Campus. Morphological evaluations (height, number of leaves, stem diameter, biomass, and root length) were performed at 40, 80, and 120 days after sowing. In the initial assessments, no significant differences were observed among treatments, indicating that all substrates provided adequate conditions for seedling establishment. However, at 120 days, the substrate composed of crushed açaí seeds, terra preta, bovine manure, and soil showed the highest values for height, number of leaves, stem diameter, and biomass, demonstrating a better balance between porosity, water retention, and nutrient availability. It is concluded that regional organic residues, especially açaí seeds combined with terra preta and bovine manure, constitute a sustainable, low-cost, and efficient alternative for the production of cacao seedlings in the Amazon region.